What are the spiciest dark romance books?

Of the 18 dark romance books smutrecs.com has rated, the spiciest are Den of Vipers (5/5), Little Stranger (5/5) and Melt for Us (5/5). 14 of the 18 are rated spice 4 or 5, on a scale from 0 to 5.

1. 
   Den of Vipers by K. A. Knight spice 5/5
2. 
   Little Stranger by Leigh Rivers spice 5/5
3. 
   Melt for Us by Molly Doyle spice 5/5
4. 
   Sabotage by Shantel Tessier spice 5/5
5. 
   Their Vicious Darling by Nikki St. Crowe spice 5/5
6. 
   Dante by Sadie Kincaid spice about 5/5
7. 
   God of Wrath by Rina Kent spice about 5/5
8. 
   Her Soul to Take by Harley Laroux spice about 5/5
9. 
   Phantom by H. D. Carlton spice about 4–5/5
10. 
    The Never King by Nikki St. Crowe spice about 4–5/5
11. 
    The Ritual by Shantel Tessier spice about 4–5/5
12. 
    Scream for Us by Molly Doyle spice 4/5
13. Glow by Raven Kennedy spice about 4/5
14. 
    Her Soul for Revenge by Harley Laroux spice about 4/5
15. 
    Black Thorns by Rina Kent spice about 3–4/5
16. 
    Carving for Cara by Dana LeeAnn spice about 3–4/5
17. 
    Our Thing by Nicci Harris spice about 3–4/5
18. 
    Tempted by Deception by Rina Kent spice about 3–4/5

Each book page lists the sources behind its ratings. Ratings marked "about" are estimates. How we rate